I already sent this to FFG, but here it is again so I can see if I'm on the right track with this.

The ammo values for the backpack ammo supply are way off. The item is stated as holding 80 shots for Plasma, Melta and Las weapons, meaning that a single pack, could fire a laspistol 80 times, or a lascannon 80 times, even though the lascannon does significantly more damage. Also, it is stated as able to be used for any ranged weapon, though there is no mention of how many needler rounds it could hold, or how many rockets, or flintlock pistol shot (sorry, I know this is nitpicking).

Also, the Hot-Shot lasgun uses a backpack power pack, which weighs 10kg, and holds 30 shots. How many backpacks can one character wear? I would say, sensibly, one. So logically, a stormtrooper, working for days, perhaps weeks behind enemy lines has 30 shots? But I can triple the weight and get another mag and a half?

There are several threads about this issue actually, though it doesn't hurt to say it again. It should be fixed.

Also, the Hot-Shot lasgun uses a backpack power pack, which weighs 10kg, and holds 30 shots. How many backpacks can one character wear? I would say, sensibly, one. So logically, a stormtrooper, working for days, perhaps weeks behind enemy lines has 30 shots?

They're Stormtroopers. They're just that good.

(Though maybe they still wouldn't say no to some reloads - sometimes, you have to kill more than 30 enemies, after all. This backpack thingy bothered me since Dark Heresy.)

Just to addd a couple of observation on this issue.

Based on precedent games a standard Lasgun connected to a Ammo Backpack has 200 shot, which are equivalent to 3 and half clips. Now I know that the 40k is all about grimdark and stuff, but no soldier right of his mind will ever replace 1.5 Kg of clips with 25 Kg of backpack.

The whole Hellgun issue is even worst.

Maybe a way to make backpack ammo packs more appealing to lasgun users is just to say that for non-heavy Las weaponry you have 'infinite' shots, but you run out if your weapon ever jams, rolls a 1 or something… needs more thought but that kind of idea. Then it would be a viable alternative to use the backpack over several regular clips.
That said i don't like having a clip weigh 10% of the weapon it is for and would prefer a proper table listing clip weights for all weapon types and classes (So Las Pistol all have a weight, las Basic all have a weight etc).

Unless you're tracking ammo by the round and weight by the ounce (or gram) then I can't see the value in breaking magazines down into "Las pistol magazine, Las rifle magazine, Heavy Laser magazine, Auto pistol magazine, auto rifle magazine, hand cannon clips, etc, etc etc etc." Frankly I don't want to get into the minutia of stripper clips vs magazines and can I get half-moon clips for my stub revolver? If you want that level of detail then house rule to your hearts content I say. If I wanted that I'd port over the rules from Morrow Project and start having to deal with blood loss affecting fatigue levels and individual wrist bones as hit locations…..

However the backpack ammo thing is absurd. 60 shots for the bog standard M36 las rifle is .4 kg, or I can have 20 shots more for only 62 times the weight? That seems like a good trade.

I dunno. For some survival scenarios tracking each individual shot and hoping you run out of xenos before you run out of bullets is a great way to add tension to a game. "Due to Eldar jamming we were dropped 27 miles from our assigned zone. We have three days and only what we have with us to get there. Fortunately Commisar Sticenbut is here to remind us that using captured Xenos weaponry is Heresy."

But for most uses I'd say Kastakas solution is the way to go, If you have a backpack power supply for your Lasgun then you run out of ammo when you roll a 100. Save a fate point.

For that matter what about Powerfists and their backpack power supply? Do they run out of juice? If that weight built into the weight of the weapon? (God I hope so, otherwise you'ld need to be built like Ahhnold in his steroid abusing days to actually use the **** things.)

Andor said:

"Apprently some wrteched and sneaky Eldar snuck past our fully alert and caffed/stimmed up sentry and slit the Commisar's neck with what was apprently a Mars-pattern serated bayonet, it was a tragedy"

But seriosuly I think the problem with the backpack ammo is that they where thinking along the lines of heavy weapons using it rather than basic las guns, so I'd run basic lasguns with the same amount of ammo that SP and Bolt weapons get, giving it 200 shots.

Andor said:

I've never played a game where you DON'T track ammo by the round. In Dark Heresy you had to buy your ammo, in rogue trader you had infinite standard ammo but could only carry so much, in deathwatch you again could only carry so much, in black crusade it was a combination of carry and purchase to some degree and in only war it'll be a case of how much you can carry. Knowing exactly when a clip is spent in order to erase it from your sheet is vital to knowing how much carrying capacity you have for assorted actions, how much your PC weighs in total (for other characters and narrative effects affecting them), and generally as a matter of game balance - the heavy weapons guy who's autocannon never runs out of ammo because he doesn't keep track of it will ruin the game for the other guys who never get a chance to kill stuff cause it's already squished.

The Backpack itself is too heavy, and from there the numbers go all wrong. Its one thing if it was slightly less efficient, but Lascannons are pretty much the only weapon where that backpack is advantageous.

The entire point of it is the efficiency of bulk purchases either in ammunition carried, and/or action economy. You HAVE to make up for most of the weight with ammunition, without forgetting [or giving nearly as much weight to as its been so far] the improvements caused by not having to reload for far longer.

Hellpistol/gun Capacitor: 80 shots, 5kg

Heavy Capacitor: 250 shots, 15kg

-Here, its a bit less efficient, but you're going 80 hell weapon shots without reloads, whereas using clips at quarter capacity would require reloading seven times for 4kg. The capacitors are too large to just plug into the gun, but they're not a rucksack. The small ones are about canteen-sized, usually affixed horizontally to the lower back, while the larger capacitors are an obvious thing, as well as a significant amount of weight.

-Some may carry a second small capacitor on occasion, but multiple heavy capacitors are rarely assigned to a trooper under most circumstances.

From here, an actual backpack rule for other weapons

Backpacks function for any clip or magazine-based weapon not stated as being fed externally in the first place. While smaller models only reduce loading times, the basic carrying frame is standardized, and efficiency improves with larger units:

Small: 5kg. Carries the equivalent of four times the normal clip capacity of a weapon.

Standard: 10kg: Holds ten times the weapon's normal ammunition capacity.

Heavy: 20kg: Holds 20 times the weapon's normal ammunition capacity in seperate packs, chambers or cells: These packs are generally used as a squad's supply rather than personal unit, and allow rapid distribution: While capable of discharging all available ammunition through the wearer's weapon, Standard clips or magazines may be replenished from the pack's capacity using a number of actions equal to the normal reload time of the weapon [rapid reload may apply].

Kasatka said:

*shrug* I've been in RT games mostly. We have yet to be in combat long enough to actually run out of ammo before returning to the ship. Laden with the weapons of our fallen foes for later resale. The orks probably have something to do with that.

I dunno. For some survival scenarios tracking each individual shot and hoping you run out of xenos before you run out of bullets is a great way to add tension to a game. "Due to Eldar jamming we were dropped 27 miles from our assigned zone. We have three days and only what we have with us to get there. Fortunately Commisar Sticenbut is here to remind us that using captured Xenos weaponry is Heresy."

So in other words: It's twentyseven miles to base, we've got a full clip of las-ammo, half a pack of lho-sticks, it's dark, and we're wearing t-shirts.

Regarding the backpack, I like Kasatka's idea - having it slowly run dry on a 100 (though, please, slowly rather than "Oops, out of ammo") sounds about right.

On any 100 would be a problem: brand new pack, empty on first shot? Just this weekend we more or less had a case where the player, if using such a backpack, would have run out on the very first shot of the game.

Slowly… could work. Way too abstract for my tastes, but if it had to be done this way:

Small backpacks like the hellgun's get one fail free, the second drops the highest [full-auto usually] RoF by 1, third you're out. Barring this weekend's player's incident, where he would've run out on the third shot anyways, its decent enough I guess.

Large would get a second freebie, but drop the RoF by fully half on that third loss.

Kiton said:

While they are not perfect I like these rules a lot more than the official ones, great job.

@Kiton

How about making it so that after rolling the first (or second?) 100, there's still one regular charge pack left?

Well to be honest i don't think rolling 100 even needs to mean it is empty: it could have jammed or siezed up or had some other issue with it that is beyond the scope of combat to fix. As such you count as Jammed and cannot clear it (except maybe with the use of Technical Knock as a Full Action) for the rest of the scene. This is precisely the situation backup weapons are for!

Kasatka said:

Maybe one can rule that on a roll of 100 the condensator in the packs overhats and they need some rounds (1d5 perhaps) to cool down before one can resume firing.

Thaddux said:

yeah the set values are a bit iffy, at the top of my head I think multiplying the weapons clip value with each weapon you pick works better.

As for the hot-shot lasgun, one can assume it basicly has a built in backpack "clip" in it´s stats, so it´s always 30 shots, because you´re already wearing a backpack "clip" by default with that one. Also remeber hot-shot Lasguns aren´t stitched to a Stormtrooper, one can assume in missions where ammo scarecity is expected they leave the hot-shot at base and bring a normal lasgun, there´s a reason all players get the items from the regiment kit.

No one in their right mind would spend resources on an expensive weapon that can't even be used in any kind of extended battle. Especially when you expect the soldier carrying that weapon can be expected to fight behind enemy lines, without resupply. "Just leave the gun at home" is a poor argument.

DJSunhammer said:

well here is a classic case where war game and rpg translation gets iffy, in the war game, Stormtroopers are basicly heavy armoured frontline fighters, where ya can argue fluff wise they have some guardsman acting as there ammo monkey fetching new backpacks from base. Of course one could house rule and give them ammo as the backpack "clip". I personally think the hot-shot is intended to be the Stormtroopers frontline gun (and it makes sense, with few expeptions a Stormtrooper player is more likely to get frontline duty then the spec ops work lore say they do) and the trooper wisely picks something else for those spec ops missions.

remmus said:

CaptainTrek said:

The standard armament of the grenadier squads is the XIV Lasgun (heavy), referred to by troops as the Hellgun, or more rarely 'hotshot' lasgun. In effect this is and overpowered lasgun, firing in the 28 megathule range and incorporating many additional features. The weapons powerpack is worn as a backpack, and the power cables run to the weapon's rapid discharge generator, which forms the weapon's main mechanism, where energy for each shot is stored. The heavy powerpack supplies enough power to keep the weapon firing for two hundred shots, depending upon the power setting and the weapon's condition.

Imperial Armour Volume 5 - The Siege of Vraks, page 88

I've looked around and that is the only source I've managed to find on the ammo capacity of Hellguns/Hotshot Lasguns.

Emperor Castaigne said:

Any indication of whether that kind of backpack would be like the lighter 10kg one or the heavier 25kg one?

Well, even if we assume the 25kg one, that's still 2.5 times the number of shots it can hold by OW or (errated) Rogue Trader RAW, so perhaps we could say the 25kg one holds 200 shots, and also increase the number of shots the lighter 10kg pack can hold by 2.5 times, resulting in it being able to carry 75 shots. That seems relatively reasonable to me…

If 'thule' is a Gothic form of joule, then the calculation is probably in megajoules per second. 28 is a LOT [just under 8kW hours] but we could be looking at a series of pulses [Lasguns causing explosions generally implies a subsequent pulse expending its energy into materials sublimated by a previous strike in a very short span of time] amounting to a fraction of a second. Even a quarter second like this, though would be roughly equivalent to concentrating a speeding pickup's impact into a very tiny area. Still, Lasers are fairly inefficient, its just that electrical power is one of those things we've really learned to convert anything into, and so its extremely plentiful..

Not taking into account the fact that 1d10+4 two-shots a normal human about half the time if you're not too unlucky [at that much energy, you'd need a lot of luck to survive just one] unless the weapon is really, really bad at transfering its energy [which given the explosions it causes, it is] and so is rather weak [it certainly fails against daemons since they mostly use TB and not AP], you're still looking at very little ammunition there. Those 16kg would be much better spent on a Long-Las with three spare charge-packs and TWENTY Krak and Frag missiles.

Speaking of missiles… Usually the missiles are much heavier and the launch unit a good deal lighter. Even the rather heavy, and anti-air [i somehow doubt there's much of a guidance unit involved in the regular guardsman krak launcher…] Stinger launcher is just 15kg, a very far cry from a 300m ranged RPG-launcher.

Yeah, I did the calculations once for another RPG. Any battery capable of giving you a lethal (let alone effective against armour) directed energy weapon good for more than a few shots is packing enough juice to run an electric car for multiple laps coast-to-coast across the US.

Your standard OW trooper is carrying around a terrifying amount of power.

And if the Imperium didn't suck at technology they could use those batteries to run rail guns instead of lasers and give the average infantry soldier a weapon capable of pithing a baneblade. Oh well.

Except they couldn't… Any weapon capable of punching through inches thick armor is going to have enough recoil to turn a human being into paste when he fires it. Not a very useful weapon to be honest.